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  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
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<body>
  <script>
    let arr = [1, 5, 9, 52]
    let res = arr.includes(5)
    console.log(res); //true

    let res2 = arr.includes(10)
    console.log(res2);//false
  </script>
</body>

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